Developmental Effects Associated with Exposure to Xylene: A Review

ABSTRACT

Data obtained from rodents indicates that maternal exposure to mixed xylenes or individual xylene isomers can have adverse effects on the conceptus. Fetotoxic effects were reported following maternal inhalation exposure to mixed xylenes; altered enzyme activities were also found in rat pups. Dermal application resulted in apparent changes in fetal enzyme activities, while oral treatment was followed by prenatal mortality, growth inhibition, and malformations, primarily cleft palate. Maternal inhalation of individual isomers was associated with all of the above mentioned effects, with the exception of cleft palate. The o^- and p^- isomers appeared more hazardous to offspring than did the m-isomer. Malformations (i.e., cleft palate) associated with mixed or individual isomers were primarily reported at maternally toxic doses. Thus, a clear case for a selective teratogenic effect due to exposure to xylene has yet to be presented.     

Second-line therapy for NSCLC in clinical practice: baseline results of the European SELECTTION observational study

Abstract

Objective:

Although the efficacy of a number of drugs for the second-line treatment of non-small cell lung cancer (NSCLC) has been demonstrated in Phase III trials, very limited evidence exists on optimal duration of second-line treatment or the reasons why this treatment is stopped in standard clinical practice. SELECTTION (Survey in European Lung Cancer Evaluating Choice of Treatment and Tolerability In Observed NSCLC) was designed to assess the time from initiation of second-line treatment for NSCLC to treatment discontinuation for any reason, the reasons for discontinuation, and the impact of discontinuation on outcomes.     

Centralized Pan-European survey on the under-treatment of hypercholesterolaemia (CEPHEUS): overall findings from eight countries

Abstract

Background:

Surveys evaluating plasma lipid goal attainment in patients with coronary heart disease have shown that hypercholesterolaemia is inadequately treated. Limited data account for the reasons behind this. The aim of the CEntralized Pan-European survey on tHE Under-treatment of hypercholeSterolaemia (CEPHEUS) survey was to evaluate the current use and efficacy of lipid-lowering drugs (LLD), and to identify possible patient/physician characteristics associated with failure to achieve low-density lipoprotein cholesterol (LDL-C) targets recommended by the 2003 European guidelines (Third Joint Task Force).     

Effects of Panax Ginseng Extract on the Benzo(a)Pyrene Metabolizing Enzyime System

ABSTRACT

Ethanol extract of Panax ginseng C. A. Meyer, which has been used for centuries as a tonic in Asian countries, exhibited a selective induction of epoxide hydratase and cytosolic glutathione transferase activity without the concurrent induction of aryl hydrocarbon hydroxylase activity. Thus, Panax ginseng appears to have the potential to alter the metabolic patterns of benzo(a)pyrene and its reactive metabolites.     

The Significance of Isomerism and Stereospecificity to the Chemistry of Plant Teratogens

Abstract

Among the stereochemical relationships which may be relevant to the biological properties of four types of teratogenic plant alkaloids are: (a) rotational isomerism about the C-20, C-22 bond of 22,26-epiminocholestenes, (b) nitrogen inversion and/or preferential ring F opening of 22α-N spirosolanes, (c) conformational or configurational interconversions of solanidanes, and (d) atropisomerism of colchicine and its analogs.     

Outcomes from the International Survey Informing Greater Insights in Opioid Dependence Treatment (INSIGHT) project

Aims: The International Survey Informing Greater Insights in Opioid Dependence Treatment (INSIGHT) study evaluated the implementation of opioid dependence treatment across different countries to assess treatment delivery, quality of care and outcomes. Methods: A questionnaire-based survey was used to gather data in nine countries across Central and Eastern Europe, South Africa and South-East Asia, from patients with opioid dependence receiving medication-assisted treatment (MAT), healthcare professionals (HCPs) who cared for opioid-dependent patients and opioid users not receiving MAT. Findings: There was substantial variation between countries, but overall results suggest that several aspects of MAT can be improved, such as access to treatment (conditions to start or remain in treatment), quality of care (availability/awareness of treatment options and appropriate medication dosing) and treatment outcomes (on-top use, misuse and diversion). Conclusions: This analysis highlights key priorities that should improve the quality of opioid dependence care and access to treatment. These priorities include: acknowledging opioid dependence as a chronic medical condition requiring long-term treatment; recognition by policymakers of the cost-effectiveness of treatment; making available, to those who want them, psychosocial interventions and educating HCPs to prescribe the safest, least divertible forms of medications available at optimal doses in order to reduce opioid use, misuse and diversion.     

Studies on Glutathione S-Transferases of Aspergillus Flavus Group in Relation to Aflatoxin Production

Abstract

Aflatoxin synthesis in the mycelia of Aspergillus is positively correlated with the activity of cellular glutathione (GSH) S-transferases (Saxena, Manju, Mukerji, K.G., Raj, H.G. 1988, Biochem. J. 254, 567-570). This finding is further extended to the action of inducer and inhibitor of aflatoxin synthesis upon A. flavus GSH S-transferase. Phenobarbitone (PB) a known inducer of aflatoxin formation increases GST activity in toxigenic strain alone as compared to non-toxigenic strains. Tinaderm (Tolnaftate) an antifungal drug specifically inhibit aflatoxin synthesis. Tinaderm - treated A. flavus mycelium was found to have significantly diminished GSH S-transferase activity coupled with reduce levels of aflatoxin. These observations point out clearly that theendogenous aflatoxin is the main factor effecting specific induction of A. flavus GSH S-transferase. The inducing effect of aflatoxin appears to be different from phenobarbital pattern of induction of GSH S-transferase. In this connection, a direct interaction of aflatoxin with A. flavus genome similar to the action of TCDD is suggested.     

Sphingomyelinase of Bacillus Cereusas a Bacterial Hemolysin

Abstract

The enzymatic, toxic and molecular properties of sphingomyelinase from Bacillus cereuswere described in relation to other bacterial sphingomyelinases such as β-toxin of Staphylococcus aureus. The complete amino acid sequences of B. cereussphingomyelinase, determined from its chromosmal DNA, were examined in relation to other phospholipases C from B. cereusand Clostridium perfringens. The gene of B. cereussphingomyelinase codes 27 amino acid residues of signal peptide and 306 residues of mature protein. Both the genes of sphingomyelinase and phosphatidylcholine-hydrolyzing phospholipase C of B. cereusformed a gene cluster. According to the prediction of secondary structure of sphingomyelinase, almost half of the total amino acid residues might participate in loop or turn structure, while one-fifth and one-fourth of amino acid residues might be involved in α-helix and β-structure, respectively. The helical content determined by circular dichroism (CD) spectra indicated 0–5%. The enzyme specifically hydrolyzes sphingomyelin in the intact erythrocyte membranes as well as in the micelles and liposomes, causing the hemolysis of erythrocytes. The enzyme is specifically adsorbed onto the surface of membranes of erythrocytes and liposomes. The hydrolysis of sphingomyelin and the adsorptive properties were influenced by the divalent metal ions such as Mg²⁺, Ca²⁺and Mn²⁺. Selective modfication of amino acid residues in the molecule of sphingomyelinase suggested that acidic amino acid residues such as Asp and Glu would be involved in the catalytic center and adsorptive sites in the sphingomyelinase molecule. Also, the effects of membrane-perturbing agents were described.     

Slaframine and Swainsonine,Mycotoxins from Rhizoctonia Leguminicola

Abstract

The mold, Rhizoctonia leguminicola, parasitizes certain legumes, e.g. red clover, in wide areas of the U.S. Consumption of such moldy forage may cause several syndromes of varying severity including excessive salivation, lacrimation, diarrhea, and even death. 1-Acetoxy-6-aminooctahydroindolizine (slaframine, SF) a parasympathomimetic, and 1,2,8-trihydroxyoctahydroindolizine (swainsonine, SW) a potent a-mannosidase inhibitor, are produced in pure R. leguminicola cultures and were also isolated directly from moldy red clover hay which had caused a severe slobbers outbreak. SW when compared with locoweed was found to produce similar effects on tissue glycosidases and oligosaccharides of the pig indicating that SW is the principal toxin responsible for the induction of locoism. Our research presently focuses on aspects of SW as a mycotoxin e.g. the possibility that SW may enter the human food chain via milk from diary cattle consuming moldy forage is being considered. Additionally we are interested in the biogenesis of SF and SW from lysine in R. leguminicola enzyme systems and if such pathways of secondary nitrogen metabolism are subject to conventional regulatory mechanisms of microbial pathways.     

Aflatoxin Related Occupational Hazards Among Rice Mill Workers

Abstract

Present study has been designed to find out the airborne mycoflora of the work environment of rice mills where workers are occupationally exposed to these environmental flora with a special reference to isolation and identification of aflatoxin positive Aspergillus strain from the work environment. The study covered altogether three rice mills located at Bawla town in Ahmedabad district (India). Of all the isolates, 27.39 were Aspergillus of which 6.64; were A. flavus. Quantitative evaluation showed the maximum number of isolates recovered from work place (P<0.01) in comparison to office (control). Strains of A. flavus were subcultured onto various qualitative media for identification of toxigenic strain, but none of the strains showed positive result indicating that all the eight strains were non-toxigenic.     

The Direct Actinc α-Fibrin(Ogen)Olytic Enzymes from Snake Venoms

Abstract

A variety of α-fibrin(ogen)olytic enzymes have been found in snake venoms. More than 15 α-fibrin(ogen)ases have been isolated and characterized. Most work has been done with the venom of snakes belonging to a few species from the Agkistrodon, Crotalus, Trimeresurus, Bothrops, and Vipera. Only one α-fibrin(ogen)olytic enzyme is characterized from Elapidae snake venoms. The enzymatic properties of these proteinases are described in relation to action on fibrinogen, fibrin, and casein. The fibrinolytic enzymes act directly on fibrin and do not activate plasminogen. The proteolytic activity of these metalloproteinases is inhibited by EDTA. Most thoroughly investigated snake venom fibrinolytic enzymes are fibrolase from Agkistrodon contortrix contortrix venom, atroxase from Crotalus atrox venom and cerastase from Cerastes cerastes venom. Antibodies to fibrolase were prepared and their cross-reactions with other fibrinolytic components from several snake venoms have been detected. These antibodies were successfully used for purification of fibrolase from crude southern copperhead venom. Fibrolase and atroxase have no hemorrhagic activity, and they effectively solubilize artificial thrombi. Research in this area has a chance to provide new therapeutic agents for dissolving thrombi.     

Therapist Rotation—A New Element in the Outpatient Treatment of Alcoholism

For nine years, the so-called “therapist rotation” has been a central part of OLITA, the Outpatient Longterm Intensive Therapy for Alcoholics. Thus far, the participation of several equally responsible therapists in the treatment of a patient has rarely been seen as a specific therapeutic approach. The present article analyzes the therapist rotation from a theoretical and clinical perspective. Articles concerned with the therapeutic alliance in the treatment of substance use disorders are reviewed. Furthermore, the literature on multiple psychotherapy, which may be seen as the precedent of the therapist rotation is surveyed. Based on the efficacy of multiple psychotherapy and the importance of the therapeutic alliance in the treatment of substance use disorders, the present work discusses the therapist rotation as an essential factor for the success of OLITA. It considers both potential advantages and disadvantages for patients and therapists and tries to identify conditions under which this approach appears to promote therapeutic interactions. Finally, the implementation of therapist rotation into OLITA is described, including the theoretical background of the program itself and the treatment procedure. New areas of application for the therapist rotation are discussed.     

Surface Lipids of Seeds Support Both Aspergillus Parasiticus Growth and Aflatoxin Production

Abstract

Seed surface lipids (SSL) play a key role in supporting aflatoxin (AFT) output in oily and starchy seeds following infection with Aspergillus parasiticus. On oily seeds, fungal growth and AFT production occur when the levels of SSL are higher than 0.15% of total oil content of seeds, with a ratio between triglycerides and free fatty acids (TG/FFA) of SSL > 1. If FFA prevail over TG, growth can be inhibited because of the toxicity towards Aspergillus of unsaturated FFA of SSL. Defatted meals of sunflower seeds support a reduced AFT biosynthesis. On starchy seeds, A. parasiticus proliferates in the germ region, the area richest in lipids.     

Mutagenicity Evaluation of Azaperone in the Salmonella/Microsome Test

ABSTRACT

Azaperone was evaluated for its mutagenic potential by the Salmonella/microsome test. No mutagenic activity towards six S. typhimurium strains could be evidenced with azaperone at doses up to 2,000 µg/plate, either without or with metabolic activation at usual test conditions. Higher concentrations of liver post-mitochondrial fraction from Aroclor 1254 (ARO)-pretreated rats did not reveal any increase in the number of revertants towards S. typhimurium strains TA1537, TA1538 and TA98. Moreover, a plate-incorporation test with liver post-mitochondrial fractions from mice pretreated with phenobarbital (PB) and a liquid preincubation test with liver post-mitochondrial fractions from rats pretreated with ARO also failed to reveal any mutagenic action of azaperone towards S. typhimurium strain TA98. Thus, none of the tests used provided any indication of azaperone having a mutagenic action.     

From a Theoretical Framework of Human Exposure and Dose Assessment to Computational System Implementation: The Modeling ENvironment for TOtal Risk Studies (MENTOR)

Georgopoulos and Lioy (1994) Georgopoulos, P. G. and Lioy, P. J. 1994. Conceptual and theoretical aspects of human exposure and dose assessment. J. Expo. Anal. Environ. Epidemiol, 4: 253–285. [CSA] [Google Scholar] presented a theoretical framework for exposure analysis, incorporating multiple levels of empirical and mechanistic information while characterizing/reducing uncertainties. The present review summarizes efforts towards implementing that framework, through the development of a mechanistic source-to-dose Modeling ENvironment for TOtal Risks studies (MENTOR), a computational toolbox that provides various modeling and data analysis tools to facilitate assessment of cumulative and aggregate (multipathway) exposures to contaminant mixtures.

MENTOR adopts a “Person Oriented Modeling” (POM) approach that can be applied to either specific individuals or to populations/subpopulations of interest; the latter is accomplished by defining samples of “virtual” individuals that statistically reproduce the physiological, demographic, etc., attributes of the populations studied. MENTOR implementations currently incorporate and expand USEPA's SHEDS (Stochastic Human Exposure and Dose Simulation) approach and consider multiple exposure routes (inhalation, food, drinking water intake; non-dietary ingestion; dermal absorption). Typically, simulations involve: (1) characterizing background levels of contaminants by combining model predictions and measurement studies; (2) characterizing multimedia levels and temporal profiles of contaminants in various residential and occupational microenvironments; (3) selecting sample populations that statistically reproduce essential demographics (age, gender, race, occupation, education) of relevant population units (e.g., census tracts); (4) developing activity event sequences for each member of the sample by matching attributes to entries of USEPA's Consolidated Human Activity Database (CHAD); (5) calculating intake rates for the sample population members, reflecting physiological attributes and activities pursued; (6) combining intake rates from multiple routes to assess exposures; (7) estimating target tissue doses with physiologically based dosimetry/toxicokinetic modeling.     

Differences in the in vivo and in vitro Effects of the Carbamate Insecticide,Carbaryl on rat Hepatic Monooxygenases

ABSTRACT

The effects of one of the most widely used insecticides, carbaryl, on the hepatic cytochrome P-450—dependent monooxygenases were determined. Addition of carbaryl to liver microsomes from untreated or phenobarbital (PB)-pretreated rats resulted in a weak Type I binding spectrum. A much stronger spectral Type I interaction was observed when microsomes from 3-methylcholanthrene(3—MC)-treated rats were used. In vitro, carbaryl caused marked inhibition of ethylmorphine and benzphetamine N-demethylases, benzo(a)pyrene hydro-xylase, 7-ethoxycoumarin and 7-ethoxyresorufin 0-deethylases in liver microsomes. Kinetic studies demonstrated that carbaryl was a competitive inhibitor of ethylmorphine N-demethylase activity. Daily administration of carbaryl for 4 days by gavage or intra-peritoneally resulted in no significant alterations in hepatic cytochrome P-450 levels, ethylmorphine N-demethylase or benzo(a)-pyrene hydroxylase activities. The lack of effect of carbaryl in vivo may be due to the rapid metabolism of the insecticide, such that the insecticide may not be present in the liver endoplasmic reticulum to cause the inhibitory effects observed in vitro.     

Comparative Study of Ceftazidime and Cefamandole in the Treatment of Patients with Infections of Skin and Soft Tissues

Abstract

Ceftazidime (Fortaz, Glaxo, Inc.) and cefamandole were compared in a randomized, prospective study of patients with infections of skin and soft tissue and/or septicemia. Infections caused by gram-positive and gram-negative bacteria were evaluated. Ceftazidime 1 gram IV every 8 hours was used in 20 patients and cefamandole 1 gram IV every 6 hours was used in 15 patients. If bacteria were not sensitive to the agent provided and if laboratory data confirmed resistance to cefamandole and susceptibility to ceftazidime, treatment was changed to ceftazidime. Bacteriological eradication of the initial pathogens and clinical improvement or cure occurred in all patients treated in each treatment group. There were no statistically significant differences (p > 0.05) between the two groups. Four patients originally placed on cefamandole were changed to ceftazidime therapy due to in vitro bacterial resistance. Each of these patients responded favorably with bacteriological eradication and clinical cure. Site of infection, age, sex and concurrent disorder were not determinants of clinical response. One patient experienced phlebitis during ceftazidime therapy; however, the infection continued to respond to IM administration of ceftazidime. Ceftazidime is safe and clinically effective in the treatment of patients with skin and soft tissue infections. It has advantages over cefamandole in the treatment of infections caused by resistant Proteus sp., E. coli, and Pseudomonas sp. Addition of a pure anti-staphylococcal agent to ceftazidime was unnecessary.     

Differential gene expression associated with inflammation and blood pressure regulation induced by concentrated ambient particle exposure

Epidemiological studies have indicated that exposure to particle matter (PM) increased the risk of respiratory and cardiovascular morbidity and mortality. It is suggested that PM smaller than 2.5 μm in aerodynamic diameter (PM_2.5) may contribute to these responses. However, the molecular mechanism is still unknown. To elucidate the changes in molecular level, we investigated the gene expression profile of concentrated ambient particles (CAPs)-exposed rats. Aged F344 rats were exposed with CAPs (594 μg/m³) or clean air 4?h per day for 3 days, and lung and heart tissues were then excised for DNA microarray analysis. Expression profiles related to inflammation and blood pressure regulation revealed differential expression of 7 genes in the lung and that of 3 genes in the heart ventricle. According to the complement activation-associated genes, complement factor B (Bf), complement component 2 and 4a (C4a), and C1 inhibitor genes were up-regulated in CAPs-exposed rat lung. Bf and C4a genes were also up-regulated in the heart. These suggest the treated animal ready for production of these proteins when activation of complement cascade is required. Pro-inflammatory cytokine, interleukin-1β, was also up-regulated in CAPs-exposed rat lung. Gene related with blood pressure regulation (angiotensin I converting enzyme) was also up-regulated in CAPs-exposed rat lung. Negative regulator of blood pressure (neuropeptide Y) was down-regulated in CAPs-exposed rat heart. These results indicate that CAPs may affect respiratory and cardiovascular organs by activation of inflammatory responses and disintegration of blood pressure regulation in early stage of CAPs exposure.     

Diazepam Metabolism in the Guinea Pig Materno-Fetal Model: Effects of Cigarette Smoke

ABSTRACT

The transplacental acquisition, disposition and biotransforma-tion of diazepam (DZ) was investigated in the pregnant guinea pig at 65–67 days of gestation following the administration of single oral doses of 10 mg/kg body weight, the dams and fetuses being euthanized 60 min post-treatment. Tissues (blood plasma, liver, brain, perirenal fat and placenta) were removed for drug residue analysis. Nordiazepam (NDZ) was the only metabolite produced by guinea pigs in vivo. Residues of DZ and NDZ were found in fetal tissues, indicating that the placenta was not an effective barrier. The influence of cigarette smoke on in vitro DZ biotransformation was studied by exposing pregnant guinea pigs (55–57 days of gestation) to ambient air (control) or cigarette smoke thrice daily for 10 consecutive days. At term (day 671, the fetuses were delivered by caesarian section for the preparation of hepatic and placental microsomes to measure the metabolism of DZ. DZ was converted at a slow rate into NDZ by fetal hepatic and placental microsomes in vitro. Exposure to cigarette smoke had no effect on DZ metabolism by the dam liver or by the placenta but a 2–4-fold increase in NDZ formation was observed in fetal hepatic microsomes.     

Comparison of Efficacy of Ginger with Various Antimotion Sickness Drugs

Abstract

Ginger and several other medications were compared with scopolamine and d-amphetamine for effectiveness in prevention of motion sickness. Methods: Double-blind techniques were used. The subjects were given the medications two hours before they were rotated in a chair making head movements until a synptun total short of vomiting was reached. Standardized N.A.S.A. techniques were used for speed of rotation and end-point of motion sickness. Results: The three doses of ginger were all at the placebo level of efficacy. Amitriptyline, ethopropazine and trihexyphenidyl increased the tolerated head movements but the increase was not statistically significant. Significant levels of protection were produced by dimenhydrinate, promethazine, scopolmine and d-amphetamine. Protection was further increased by combination of these latter drugs with d-amphetamine. Efficacy was greatest as the dose was increased. Conclusions: The medication of choice in this study was scopolamine 0.6 mg with d-amphetamine 10 mg. This combination provided good protection with acceptable side effects.